package com.tianji.learning.service.impl;

import com.tianji.common.autoconfigure.mq.RabbitMqHelper;
import com.tianji.common.constants.MqConstants;
import com.tianji.common.exceptions.BizIllegalException;
import com.tianji.common.utils.CollUtils;
import com.tianji.common.utils.UserContext;
import com.tianji.learning.constants.RedisConstants;
import com.tianji.learning.mq.msg.SignInMessage;
import com.tianji.learning.service.SignRecordService;
import com.tianji.learning.vo.SignResultVO;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.data.redis.connection.BitFieldSubCommands;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.util.List;

@Service
@RequiredArgsConstructor
@Slf4j
public class SignRecordServiceImpl implements SignRecordService {

    private final StringRedisTemplate redisTemplate;

    private final RabbitMqHelper rabbitMqHelper;


    @Override
    public SignResultVO addSignRecords() {
        // 1.获取用户id
        Long userId = UserContext.getUser();
        // 2.拼接key
        LocalDate now = LocalDate.now();//当前时间的年月
        String format = now.format(DateTimeFormatter.ofPattern(":yyyyMM"));//得到：年月   格式化字符串
        String key = RedisConstants.SIGN_RECORD_KEY_PREFIX + userId.toString() + format;
        // 3.利用bitset命令保存到redis中  需要判断是否已签到
        int offset = now.getDayOfMonth() - 1;
        Boolean setBit = redisTemplate.opsForValue().setBit(key, offset, true);
        if (setBit) {
            // 说明已经签到过了
            throw new BizIllegalException("已经签到过了，不能重复签到");
        }

        // 4.计算连续签到的天数
        int days = countSignDays(key, now.getDayOfMonth());


        // 5.计算奖励积分
        int rewardPoints = 0; // 代表连续签到 奖励积分
        switch (days) {
            case 7:
                rewardPoints = 10;
                break;
            case 14:
                rewardPoints = 20;
                break;
            case 28:
                rewardPoints = 40;
                break;
        }

        //  6.保存积分  发送消息到MQ
        rabbitMqHelper.send(MqConstants.Exchange.LEARNING_EXCHANGE,
                MqConstants.Key.SIGN_IN,
                SignInMessage.of(userId, rewardPoints + 1));

        // 7.封装vo返回
        SignResultVO vo = new SignResultVO();
        vo.setSignDays(days);
        vo.setRewardPoints(rewardPoints);

        return vo;
    }

    @Override
    public Byte[] querySignRecords() {
        // 1.获取用户id
        Long userId = UserContext.getUser();

        // 2.拼接key
        LocalDate now = LocalDate.now();//当前时间的年月
        String format = now.format(DateTimeFormatter.ofPattern(":yyyyMM"));//得到：年月   格式化字符串
        String key = RedisConstants.SIGN_RECORD_KEY_PREFIX + userId.toString() + format;

        // 3.利用redis bitfield命令查询第一天到今天的所有签到记录
        int dayOfMonth = now.getDayOfMonth();
        List<Long> bitField = redisTemplate.opsForValue().bitField(key,
                BitFieldSubCommands.create().get(BitFieldSubCommands.BitFieldType.unsigned(dayOfMonth)).valueAt(0));
        if (CollUtils.isEmpty(bitField)) {
            return new Byte[0];
        }
        Long num = bitField.get(0);
        int offset = dayOfMonth - 1;
        // 4.利用与运算和位移 封装结构
        Byte[] arr = new Byte[dayOfMonth];
        while (offset >= 0) {
            arr[offset] = (byte) (num & 1);
            num = num >>> 1;
            offset--;
        }
        return arr;
    }

    /**
     * 计算连续签到天数
     * @param key        缓存的key
     * @param dayOfMonth 本月第一天到今天的 天数
     * @return
     */
    private int countSignDays(String key, int dayOfMonth) {
        // 1.求本月第一天到今天的所有签到数据
        List<Long> bitField = redisTemplate.opsForValue().bitField(key,
                BitFieldSubCommands.create().get(BitFieldSubCommands.BitFieldType.unsigned(dayOfMonth)).valueAt(0));
        if (CollUtils.isEmpty(bitField)) {
            return 0;
        }
        Long num = bitField.get(0);  //本月第一天到今天的签到数据 拿到的十进制数
        log.debug("本月签到数据：{}", num);

        // 2.num转为2进制  从后往前看有多少个1  与运算
        int counter = 0;
        while ((num & 1) == 1) {
            counter++;
            num = num >>> 1; //右移一位
        }
        return counter;
    }
}
